Metabolic outcomes in obese mice undergoing one-anastomosis gastric bypass (OAGB) with a long or a short biliopancreatic limb

One-anastomosis gastric bypass (OAGB) has gained importance as a safe and effective operation to treat morbid obesity. It is not known whether a long biliopancreatic limb (BPL) in OAGB surgery compared to a short BPL results in beneficial metabolic outcomes. 5-week-old male C57BL/6J mice fed a high-fat diet for 8 weeks underwent OAGB surgery with defined short and long BPL lengths, or sham surgery combined with caloric restriction. Weight loss, glucose tolerance, obesity-related comorbidities, endocrine effects, gut microbiota and bile acids were assessed. Total weight loss was independent of the length of the BPL after OAGB surgery. However, a long BPL was associated with lower glucose-stimulated insulin on day 14, and an improved glucose tolerance on day 35 after surgery. A long BPL resulted in reduced total cholesterol. There were no differences in the resolution of metabolic dysfunction-associated steatotic liver disease and adipose tissue inflammation. Tendencies of an attenuated hypothalamic-pituitary-adrenal axis and aldosterone were present in the long BPL group. In OAGB-operated mice, we found an increase in primary conjugated bile acids (pronounced in long BPL) along with a loss in bacterial Desulfovibrionaceae and Erysipelotrichaceae and simultaneous increase in Akkermansiaceae, Sutterellaceae and Enterobacteriaceae. In sum, OAGB surgery with a long compared to a short BPL led to similar weight loss, but improved glucose metabolism, lipid and endocrine outcomes in obese mice, potentially mediated through changes in gut microbiota and related bile acids. Tailoring the BPL length in humans might help to optimize metabolic outcomes after bariatric surgery.

Protocol for isolation and spectral flow cytometry analysis of immune cells from the murine exocrine and endocrine pancreas

Diabetes mellitus is a disease of the hormone-secreting endocrine pancreas. However, increasing evidence suggests that the exocrine pancreas is also involved in the pathogenesis of diabetes. In this protocol, we describe how to harvest both isolated islets and exocrine tissue from one mouse pancreas, followed by a detailed explanation of how to isolate and analyze immune cells using full-spectrum flow cytometry.

CSF1R inhibition with PLX5622 affects multiple immune cell compartments and induces tissue-specific metabolic effects in lean mice

AIMS/HYPOTHESIS

Colony stimulating factor 1 (CSF1) promotes the proliferation, differentiation and survival of macrophages, which have been implicated in both beneficial and detrimental effects on glucose metabolism. However, the physiological role of CSF1 signalling in glucose homeostasis and the potential therapeutic implications of modulating this pathway are not known. We aimed to study the composition of tissue macrophages (and other immune cells) following CSF1 receptor (CSF1R) inhibition and elucidate the metabolic consequences of CSF1R inhibition.

METHODS

We assessed immune cell populations in various organs by flow cytometry, and tissue-specific metabolic effects by hyperinsulinaemic-euglycaemic clamps and insulin secretion assays in mice fed a chow diet containing PLX5622 (a CSF1R inhibitor) or a control diet.

RESULTS

CSF1R inhibition depleted macrophages in multiple tissues while simultaneously increasing eosinophils and group 2 innate lymphoid cells. These immunological changes were consistent across different organs and were sex independent and reversible after cessation of the PLX5622. CSF1R inhibition improved hepatic insulin sensitivity but concomitantly impaired insulin secretion. In healthy islets, we found a high frequency of IL-1β+ islet macrophages. Their depletion by CSF1R inhibition led to downregulation of macrophage-related pathways and mediators of cytokine activity, including Nlrp3, suggesting IL-1β as a candidate insulin secretagogue. Partial restoration of physiological insulin secretion was achieved by injecting recombinant IL-1β prior to glucose stimulation in mice lacking macrophages.

CONCLUSIONS/INTERPRETATION

Macrophages and macrophage-derived factors, such as IL-1β, play an important role in physiological insulin secretion. A better understanding of the tissue-specific effects of CSF1R inhibition on immune cells and glucose homeostasis is crucial for the development of targeted immune-modulatory treatments in metabolic disease.

DATA AVAILABILITY

The RNA-Seq dataset is available in the Gene Expression Omnibus (GEO) under the accession number GSE189434 ( http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE189434 ).

Obligate chimerism in male yellow crazy ants

Multicellular organisms typically develop from a single fertilized egg and therefore consist of clonal cells. We report an extraordinary reproductive system in the yellow crazy ant. Males are chimeras of haploid cells from two divergent lineages: R and W. R cells are overrepresented in the males' somatic tissues, whereas W cells are overrepresented in their sperm. Chimerism occurs when parental nuclei bypass syngamy and divide separately within the same egg. When syngamy takes place, the diploid offspring either develops into a queen when the oocyte is fertilized by an R sperm or into a worker when fertilized by a W sperm. This study reveals a mode of reproduction that may be associated with a conflict between lineages to preferentially enter the germ line.

Lung versus gut exposure to air pollution particles differentially affect metabolic health in mice

BACKGROUND

Air pollution has emerged as an unexpected risk factor for diabetes. However, the mechanism behind remains ill-defined. So far, the lung has been considered as the main target organ of air pollution. In contrast, the gut has received little scientific attention. Since air pollution particles can reach the gut after mucociliary clearance from the lungs and through contaminated food, our aim was to assess whether exposure deposition of air pollution particles in the lung or the gut drive metabolic dysfunction in mice.

METHODS

To study the effects of gut versus lung exposure, we exposed mice on standard diet to diesel exhaust particles (DEP; NIST 1650b), particulate matter (PM; NIST 1649b) or phosphate-buffered saline by either intratracheal instillation (30 µg 2 days/week) or gavage (12 µg 5 days/week) over at least 3 months (total dose of 60 µg/week for both administration routes, equivalent to a daily inhalation exposure in humans of 160 µg/m³ PM_2.5) and monitored metabolic parameters and tissue changes. Additionally, we tested the impact of the exposure route in a "prestressed" condition (high-fat diet (HFD) and streptozotocin (STZ)).

RESULTS

Mice on standard diet exposed to particulate air pollutants by intratracheal instillation developed lung inflammation. While both lung and gut exposure resulted in increased liver lipids, glucose intolerance and impaired insulin secretion was only observed in mice exposed to particles by gavage. Gavage with DEP created an inflammatory milieu in the gut as shown by up-regulated gene expression of pro-inflammatory cytokines and monocyte/macrophage markers. In contrast, liver and adipose inflammation markers were not increased. Beta-cell secretory capacity was impaired on a functional level, most likely induced by the inflammatory milieu in the gut, and not due to beta-cell loss. The differential metabolic effects of lung and gut exposures were confirmed in a "prestressed" HFD/STZ model.

CONCLUSIONS

We conclude that separate lung and gut exposures to air pollution particles lead to distinct metabolic outcomes in mice. Both exposure routes elevate liver lipids, while gut exposure to particulate air pollutants specifically impairs beta-cell secretory capacity, potentially instigated by an inflammatory milieu in the gut.

Educational Inequalities at the Intersection of Multiple Social Categories: An Introduction and Systematic Review of the Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA) Approach

Intersectional approaches have become increasingly important for explaining educational inequalities because they help to improve our understanding of how individual experiences are shaped by simultaneous membership in multiple social categories that are associated with interconnected systems of power, privilege, and oppression. For years, there has been a call in psychological and educational research for quantitative approaches that can account for the intersection of multiple social categories. The present paper introduces the Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA) approach, a novel intersectional approach from epidemiology, to study educational inequalities. The MAIHDA approach uses a multilevel model as the statistical framework to define intersectional strata that represent individuals’ membership in multiple social categories. By partitioning the variance within and between intersectional strata, the MAIHDA approach allows identifying intersectional effects at the strata level as well as obtaining information on the discriminatory accuracy of these strata for predicting individual educational outcomes. Compared to conventional quantitative intersectional approaches, MAIHDA analyses have several advantages, including better scalability for higher dimensions, model parsimony, and precision-weighted estimates of strata with small sample sizes. We provide a systematic review of its past application and illustrate its use by analyzing inequalities in reading achievement across 40 unique intersectional strata (combining the social categories of gender, immigrant background, parental education, and parental occupational status) using data from 15-year-old students in Germany (N = 5451). We conclude that the MAIHDA approach is a valuable intersectional tool to study inequalities in educational contexts.

Persicamidines-Unprecedented Sesquarterpenoids with Potent Antiviral Bioactivity against Coronaviruses

A new family of highly unusual sesquarterpenoids (persicamidines A-E) exhibiting significant antiviral activity was isolated from a newly discovered actinobacterial strain, Kibdelosporangium persicum sp. nov., collected from a hot desert in Iran. Extensive NMR analysis unraveled a hexacyclic terpenoid molecule with a modified sugar moiety on one side and a highly unusual isourea moiety fused to the terpenoid structure. The structures of the five analogues differed only in the aminoalkyl side chain attached to the isourea moiety. Persicamidines A-E showed potent activity against hCoV-229E and SARS-CoV-2 viruses in the nanomolar range together with very good selectivity indices, making persicamidines promising as starting points for drug development.

Meta-analyzing individual participant data from studies with complex survey designs: A tutorial on using the two-stage approach for data from educational large-scale assessments

Descriptive analyses of socially important or theoretically interesting phenomena and trends are a vital component of research in the behavioral, social, economic, and health sciences. Such analyses yield reliable results when using representative individual participant data (IPD) from studies with complex survey designs, including educational large-scale assessments (ELSAs) or social, health, and economic survey and panel studies. The meta-analytic integration of these results offers unique and novel research opportunities to provide strong empirical evidence of the consistency and generalizability of important phenomena and trends. Using ELSAs as an example, this tutorial offers methodological guidance on how to use the two-stage approach to IPD meta-analysis to account for the statistical challenges of complex survey designs (e.g., sampling weights, clustered and missing IPD), first, to conduct descriptive analyses (Stage 1), and second, to integrate results with three-level meta-analytic and meta-regression models to take into account dependencies among effect sizes (Stage 2). The two-stage approach is illustrated with IPD on reading achievement from the Programme for International Student Assessment (PISA). We demonstrate how to analyze and integrate standardized mean differences (e.g., gender differences), correlations (e.g., with students' socioeconomic status [SES]), and interactions between individual characteristics at the participant level (e.g., the interaction between gender and SES) across several PISA cycles. All the datafiles and R scripts we used are available online. Because complex social, health, or economic survey and panel studies share many methodological features with ELSAs, the guidance offered in this tutorial is also helpful for synthesizing research evidence from these studies.

Targeting colonic macrophages improves glycemic control in high-fat diet-induced obesity

The obesity epidemic continues to worsen worldwide. However, the mechanisms initiating glucose dysregulation in obesity remain poorly understood. We assessed the role that colonic macrophage subpopulations play in glucose homeostasis in mice fed a high-fat diet (HFD). Concurrent with glucose intolerance, pro-inflammatory/monocyte-derived colonic macrophages increased in mice fed a HFD. A link between macrophage numbers and glycemia was established by pharmacological dose-dependent ablation of macrophages. In particular, colon-specific macrophage depletion by intrarectal clodronate liposomes improved glucose tolerance, insulin sensitivity, and insulin secretion capacity. Colonic macrophage activation upon HFD was characterized by an interferon response and a change in mitochondrial metabolism, which converged in mTOR as a common regulator. Colon-specific mTOR inhibition reduced pro-inflammatory macrophages and ameliorated insulin secretion capacity, similar to colon-specific macrophage depletion, but did not affect insulin sensitivity. Thus, pharmacological targeting of colonic macrophages could become a potential therapy in obesity to improve glycemic control.

Expansion of pro-inflammatory macrophages in the colon occurs early after high-fat diet initiation, prior to macrophage accumulation in the adipose tissue, in a microbiome-dependent fashion. Macrophage depletion systemically and/or exclusively in the colon improves glucose metabolism.

Structure and Biosynthesis of Myxofacyclines: Unique Myxobacterial Polyketides Featuring Varing and Rare Heterocycles[] *

A metabolome-guided screening approach in the novel myxobacterium Corallococcus sp. MCy9072 resulted in the isolation of the unprecedented natural product myxofacycline A, which features a rare isoxazole substructure. Identification and genomic investigation of additional producers alongside targeted gene inactivation experiments and heterologous expression of the corresponding biosynthetic gene cluster in the host Myxococcus xanthus DK1622 confirmed a noncanonical megaenzyme complex as the biosynthetic origin of myxofacycline A. Induced expression of the respective genes led to significantly increased production titers enabling the identification of six further members of the myxofacycline natural product family. Whereas myxofacyclines A-D display an isoxazole substructure, intriguingly myxofacyclines E and F were found to contain 4-pyrimidinole, a heterocycle unprecedented in natural products. Lastly, myxofacycline G features another rare 1,2-dihydropyrol-3-one moiety. In addition to a full structure elucidation, we report the underlying biosynthetic machinery and present a rationale for the formation of all myxofacyclines. Unexpectedly, an extraordinary polyketide synthase-nonribosomal peptide synthetase hybrid was found to produce all three types of heterocycle in these natural products.

Obesity in Humans Is Characterized by Gut Inflammation as Shown by Pro-Inflammatory Intestinal Macrophage Accumulation

Chronic low-grade inflammation is a hallmark of obesity and associated with cardiovascular complications. However, it remains unclear where this inflammation starts. As the gut is constantly exposed to food, gut microbiota, and metabolites, we hypothesized that mucosal immunity triggers an innate inflammatory response in obesity. We characterized five distinct macrophage subpopulations (P1-P5) along the gastrointestinal tract and blood monocyte subpopulations (classical, non-classical, intermediate), which replenish intestinal macrophages, in non-obese (BMI<27kg/m²) and obese individuals (BMI>32kg/m²). To elucidate factors that potentially trigger gut inflammation, we correlated these subpopulations with cardiovascular risk factors and lifestyle behaviors. In obese individuals, we found higher pro-inflammatory macrophages in the stomach, duodenum, and colon. Intermediate blood monocytes were also increased in obesity, suggesting enhanced recruitment to the gut. We identified unhealthy lifestyle habits as potential triggers of gut and systemic inflammation (i.e., low vegetable intake, high processed meat consumption, sedentary lifestyle). Cardiovascular risk factors other than body weight did not affect the innate immune response. Thus, obesity in humans is characterized by gut inflammation as shown by accumulation of pro-inflammatory intestinal macrophages, potentially via recruited blood monocytes. Understanding gut innate immunity in human obesity might open up new targets for immune-modulatory treatments in metabolic disease.

[Gut microbiome and anorexia nervosa : The relationship between microbiome and gut-brain interaction in the context of anorexia nervosa]

In recent years the intestinal microbiome and its interaction with the brain has aroused a growing interest. The findings gained in the course of this research are of great relevance not only to basic scientists but also to clinicians, as studies suggest an association between an altered microbiome and various somatic (e.g. chronic inflammatory intestinal diseases, obesity and diabetes) as well as psychiatric diseases (e.g. anxiety disorders, depression). In addition to a direct influence of the microbiome on the brain and behavior, various mechanisms seem to be relevant, including altered energy intake from food, hormonal changes, probably increased intestinal permeability as well as inflammatory and immunological processes. Anorexia nervosa (AN) is the third most common chronic disease in adolescence and has the highest mortality rate among all mental disorders. In addition to extremely restrictive eating habits, weight loss and comorbid anxiety and depression symptoms, endocrine changes and an increased autoimmune and inflammatory response are characteristic. Since AN is particularly strongly linked to eating behavior and nutrition, research into the microbiome seems very promising, especially with respect to this disease. This article gives a first insight into the underlying processes that play a role in gut-brain interaction in the context of AN and summarizes the previous empirical findings on this topic. Finally, an outlook on future research and possible implications for the therapeutic practice and treatment of AN is given.

Palstimolide A: A Complex Polyhydroxy Macrolide with Antiparasitic Activity

Marine Cyanobacteria (blue-green algae) have been shown to possess an enormous potential to produce structurally diverse natural products that exhibit a broad spectrum of potent biological activities, including cytotoxic, antifungal, antiparasitic, antiviral, and antibacterial activities. Here, we report the isolation and structure determination of palstimolide A, a complex polyhydroxy macrolide with a 40-membered ring that was isolated from a tropical marine cyanobacterium collected at Palmyra Atoll. NMR-guided fractionation in combination with MS²-based molecular networking and isolation via HPLC yielded 0.7 mg of the pure compound. The small quantity isolated along with the presence of significant signal degeneracy in both the ¹H and ¹³C-NMR spectra complicated the structure elucidation of palstimolide A. Various NMR experiments and solvent systems were employed, including the LR-HSQMBC experiment that allows the detection of long-range ¹H–¹³C correlation data across 4-, 5-, and even 6-bonds. This expanded NMR data set enabled the elucidation of the palstimolide’s planar structure, which is characterized by several 1,5-disposed hydroxy groups as well as a tert-butyl group. The compound showed potent antimalarial activity with an IC₅₀ of 223 nM as well as interesting anti-leishmanial activity with an IC₅₀ of 4.67 µM.

Tutuilamides A-C: Vinyl-Chloride-Containing Cyclodepsipeptides from Marine Cyanobacteria with Potent Elastase Inhibitory Properties

Marine cyanobacteria (blue-green algae) have been shown to possess an enormous capacity to produce structurally diverse natural products that exhibit a broad spectrum of potent biological activities, including cytotoxic, antifungal, antiparasitic, antiviral, and antibacterial activities. Using mass-spectrometry-guided fractionation together with molecular networking, cyanobacterial field collections from American Samoa and Palmyra Atoll yielded three new cyclic peptides, tutuilamides A-C. Their structures were established by spectroscopic techniques including 1D and 2D NMR, HR-MS, and chemical derivatization. Structure elucidation was facilitated by employing advanced NMR techniques including nonuniform sampling in combination with the 1,1-ADEQUATE experiment. These cyclic peptides are characterized by the presence of several unusual residues including 3-amino-6-hydroxy-2-piperidone and 2-amino-2-butenoic acid, together with a novel vinyl chloride-containing residue. Tutuilamides A-C show potent elastase inhibitory activity together with moderate potency in H-460 lung cancer cell cytotoxicity assays. The binding mode to elastase was analyzed by X-ray crystallography revealing a reversible binding mode similar to the natural product lyngbyastatin 7. The presence of an additional hydrogen bond with the amino acid backbone of the flexible side chain of tutuilamide A, compared to lyngbyastatin 7, facilitates its stabilization in the elastase binding pocket and possibly explains its enhanced inhibitory potency.

Tunable anomalous Hall conductivity through volume-wise magnetic competition in a topological kagome magnet

Magnetic topological phases of quantum matter are an emerging frontier in physics and material science. Along these lines, several kagome magnets have appeared as the most promising platforms. Here, we explore magnetic correlations in the kagome magnet Co3Sn2S2. Using muon spin-rotation, we present evidence for competing magnetic orders in the kagome lattice of this compound. Our results show that while the sample exhibits an out-of-plane ferromagnetic ground state, an in-plane antiferromagnetic state appears at temperatures above 90 K, eventually attaining a volume fraction of 80% around 170 K, before reaching a non-magnetic state. Strikingly, the reduction of the anomalous Hall conductivity (AHC) above 90 K linearly follows the disappearance of the volume fraction of the ferromagnetic state. We further show that the competition of these magnetic phases is tunable through applying either an external magnetic field or hydrostatic pressure. Our results taken together suggest the thermal and quantum tuning of Berry curvature induced AHC via external tuning of magnetic order.

Cyclins B1, T1, and H differ in their molecular mode of interaction with cytomegalovirus protein kinase pUL97

Human cytomegalovirus (HCMV) is a common β-herpesvirus causing life-long latent infections. HCMV replication interferes with cell cycle regulation in host cells because the HCMV-encoded cyclin-dependent kinase (CDK) ortholog pUL97 extensively phosphorylates the checkpoint regulator retinoblastoma protein. pUL97 also interacts with cyclins B1, T1, and H, and recent findings have strongly suggested that these interactions influence pUL97 substrate recognition. Interestingly, here we detected profound mechanistic differences among these pUL97-cyclin interactions. Our study revealed the following. (i) pUL97 interacts with cyclins B1 and H in a manner dependent on pUL97 activity and HCMV-specific cyclin modulation, respectively. (ii) The phosphorylated state of both proteins is an important determinant of the pUL97-cyclin B1 interaction. (iii) Activated phospho-Thr-315 cyclin H is up-regulated during HCMV replication. (iv) Thr-315 phosphorylation is independent of intracellular pUL97 or CDK7 activity. (v) pUL97-mediated in vitro phosphorylation is detectable for cyclin B1 but not H. (vi) Mutual transphosphorylation between pUL97 and CDK7 is not detectable, and an MS-based phosphosite analysis indicated that pUL97 might unexpectedly not be phosphorylated in its T-loop. (vii) The binary complexes pUL97-cyclin H and CDK7-cyclin H as well as the ternary complex pUL97-cyclin-H-CDK7 are detectable in an assembly-based CoIP approach. (viii) pUL97 self-interaction can be bridged by the transcriptional cyclins T1 or H but not by the classical cell cycle-regulating B1 cyclin. Combined, our findings unravel a number of cyclin type-specific differences in pUL97 interactions and suggest a multifaceted regulatory impact of cyclins on HCMV replication.

Pauling Entropy, Metastability, and Equilibrium in Dy_{2}Ti_{2}O_{7} Spin Ice

Determining the fate of the Pauling entropy in the classical spin ice material Dy_{2}Ti_{2}O_{7} with respect to the third law of thermodynamics has become an important test case for understanding the existence and stability of ice-rule states in general. The standard model of spin ice-the dipolar spin ice model-predicts an ordering transition at T≈0.15  K, but recent experiments by Pomaranski et al. suggest an entropy recovery over long timescales at temperatures as high as 0.5 K, much too high to be compatible with the theory. Using neutron scattering and specific heat measurements at low temperatures and with long timescales (0.35  K/10^{6}  s and 0.5  K/10^{5}  s, respectively) on several isotopically enriched samples, we find no evidence of a reduction of ice-rule correlations or spin entropy. High-resolution simulations of the neutron structure factor show that the spin correlations remain well described by the dipolar spin ice model at all temperatures. Furthermore, by careful consideration of hyperfine contributions, we conclude that the original entropy measurements of Ramirez et al. are, after all, essentially correct: The short-time relaxation method used in that study gives a reasonably accurate estimate of the equilibrium spin ice entropy due to a cancellation of contributions.

Bone Marrow Stromal Cells Promote Innervation of Bioengineered Teeth

Transplantation of bone marrow mesenchymal stem cells (BMDCs) into a denervated side of the spinal cord was reported to be a useful option for axonal regeneration. The innervation of teeth is essential for their function and protection but does not occur spontaneously after injury. Cultured reassociations between dissociated embryonic dental mesenchymal and epithelial cells and implantation lead to a vascularized tooth organ regeneration. However, when reassociations were coimplanted with a trigeminal ganglion (TG), innervation did not occur. On the other hand, reassociations between mixed embryonic dental mesenchymal cells and bone marrow-derived cells isolated from green fluorescent protein (GFP) transgenic mice (BMDCs-GFP) (50/50) with an intact and competent dental epithelium (ED14) were innervated. In the present study, we verified the stemness of isolated BMDCs, confirmed their potential role in the innervation of bioengineered teeth, and analyzed the mechanisms by which this innervation can occur. For that purpose, reassociations between mixed embryonic dental mesenchymal cells and BMDCs-GFP with an intact and competent dental epithelium were cultured and coimplanted subcutaneously with a TG for 2 wk in ICR mice. Axons entered the dental pulp and reached the odontoblast layer. BMDCs-GFP were detected at the base of the tooth, with some being present in the pulp associated with the axons. Thus, while having a very limited contribution in tooth formation, they promoted the innervation of the bioengineered teeth. Using quantitative reverse transcription polymerase chain reaction and immunostainings, BMDCs were shown to promote innervation by 2 mechanisms: 1) via immunomodulation by reducing the number of T lymphocytes (CD3+, CD25+) in the implants and 2) by expressing neurotrophic factors such as NGF, BDNF, and NT3 for axonal growth. This strategy using autologous mesenchymal cells coming from bone marrow could be used to innervate bioengineered teeth without treatment with an immunosuppressor such as cyclosporine A (CsA), thus avoiding multiple side effects.

Dipolar Spin Ice States with a Fast Monopole Hopping Rate in CdEr_{2}X_{4} (X=Se, S)

Excitations in a spin ice behave as magnetic monopoles, and their population and mobility control the dynamics of a spin ice at low temperature. CdEr_{2}Se_{4} is reported to have the Pauling entropy characteristic of a spin ice, but its dynamics are three orders of magnitude faster than the canonical spin ice Dy_{2}Ti_{2}O_{7}. In this Letter we use diffuse neutron scattering to show that both CdEr_{2}Se_{4} and CdEr_{2}S_{4} support a dipolar spin ice state-the host phase for a Coulomb gas of emergent magnetic monopoles. These Coulomb gases have similar parameters to those in Dy_{2}Ti_{2}O_{7}, i.e., dilute and uncorrelated, and so cannot provide three orders faster dynamics through a larger monopole population alone. We investigate the monopole dynamics using ac susceptometry and neutron spin echo spectroscopy, and verify the crystal electric field Hamiltonian of the Er^{3+} ions using inelastic neutron scattering. A quantitative calculation of the monopole hopping rate using our Coulomb gas and crystal electric field parameters shows that the fast dynamics in CdEr_{2}X_{4} (X=Se, S) are primarily due to much faster monopole hopping. Our work suggests that CdEr_{2}X_{4} offer the possibility to study alternative spin ice ground states and dynamics, with equilibration possible at much lower temperatures than the rare earth pyrochlore examples.

Immune mediated destruction of platelets in dogs with heat stroke: A prospective study

Objective: Severe thrombocytopenia is a common sequelae to heat stroke in dogs. So far it has been hypothezised that it is due to disseminated intravascular coagulation. We hypothezised that it is due to immune mediated destruction via antiplatelet antibodies. Material and methods: Prospective evaluation of dogs with heat stroke from May 2005 to August 2008. Dogs that developed severe thrombocytopenia within 5 days of admission were included in the study. All dogs were treated with a standardized treatment protocol. In addition, they received either immunoglobulins or prednisolone. Results: Six dogs were presented with heat stroke during that time period. Four developed a severe thrombocytopenia. All four dogs tested positive for antiplatelet antibodies and did not have elevated D-Dimers at that time. Platelet count in three dogs recovered fully, one dog was euthanized due to liver and renal failure. Conclusion: In those cases thrombocytopenia was due to immune mediated destruction not due to DIC. Clinical rele-vance: Due to the severity of the thrombocytopenia and the high risk for bleeding in those patients, immunosuppressive therapy in addition to DIC prophylaxis should be discussed.

Fallbericht und Literaturübersicht kutaner Dirofilariose

Gegenstand und Ziel: Der Fallbericht erörtert das diagnostische Vorgehen und differenzialdiagnostische Überlegungen bei Patienten mit Mikrofilarämie und negativem Dirofilaria-immitis-Antigentest und diskutiert die Infektion mit Dirofilaria repens und deren Therapie. Material und Methode: Bei einem Hund aus Ungarn wurden im Blutausstrich Mikrofilarien gefunden. Die weitere Diagnostik zur Differenzierung der Mikrofilarien umfasste einen Dirofilaria-immitis-Antigentest, eine Polymerasekettenreaktion zum Nachweis von Dirofilaria immitis und Dipetalonema reconditum sowie eine Saure-Phosphatase-Reaktion zur Diagnose einer Infektion mit Dirofilaria repens. Ergebnisse: Mittels der Saure-Phosphatase-Reaktion konnte eine Infektion mit Dirofilaria repens diagnostiziert werden. Die Therapie gegen die Mikrofilarien erfolgte mit Selamectin. Schlussfolgerung und klinische Relevanz: Bei mikrofilarämischen Patienten muss differenzialdiagnostisch neben einer Infektion mit Dirofilaria immitis eine Infektion mit anderen, weniger pathogenen Parasiten in Betracht gezogen werden, da sich die Notwendigkeit einer Therapie und das Therapieregime je nach Infektion deutlich unterscheiden.

World Health Organization cardiovascular risk stratification and target organ damage

BACKGROUND

Prediction charts allow treatment to be targeted according to simple markers of cardiovascular risk; many algorithms do not recommend screening asymptomatic target organ damage which could change dramatically the assessment.

OBJECTIVE

To demonstrate that target organ damage is present in low cardiovascular risk hypertensive patients and it is more frequent and severe as global cardiovascular risk increases.

METHODS

Consecutive hypertensive patients treated at a single Latin American center. Cardiovascular risk stratified according to 2013 WHO/ISH risk prediction chart America B. Left ventricular mass assessed by Devereux method, left ventricular hypertrophy considered >95g/m(2) in women and >115g/m(2) in men. Transmitral diastolic peak early flow velocity to average septal/lateral peak early diastolic relaxation velocity (E/e' ratio) measured cut off value >13. Systolic function assessed by tissue Doppler average interventricular septum/lateral wall mitral annulus rate systolic excursion (s wave).

RESULTS

A total of 292 patients were included of whom 159 patients (54.5%) had cardiovascular risk of <10%, 90 (30.8%) had cardiovascular risk of 10-20% and 43 (14.7%) had cardiovascular risk of >20%. Left ventricular hypertrophy was detected in 17.6% low risk patients, 27.8% in medium risk and 23.3% in high risk (p<0.05), abnormal E/e' ratio was found in 13.8%, 31.1% and 27.9%, respectively (p<0.05). Mean s wave was 8.03+8, 8.1+9 and 8.7+1cm/s for low, intermediate and high risk patients, respectively (p<0.025).

CONCLUSIONS

Target organ damage is more frequent and severe in high risk; one over four subjects was misclassified due to the presence of asymptomatic target organ damage.

Development of a Potent Inhibitor of the Plasmodium Proteasome with Reduced Mammalian Toxicity

Naturally derived chemical compounds are the foundation of much of our pharmacopeia, especially in antiproliferative and anti-infective drug classes. Here, we report that a naturally derived molecule called carmaphycin B is a potent inhibitor against both the asexual and sexual blood stages of malaria infection. Using a combination of in silico molecular docking and in vitro directed evolution in a well-characterized drug-sensitive yeast model, we determined that these compounds target the β5 subunit of the proteasome. These studies were validated using in vitro inhibition assays with proteasomes isolated from Plasmodium falciparum. As carmaphycin B is toxic to mammalian cells, we synthesized a series of chemical analogs that reduce host cell toxicity while maintaining blood-stage and gametocytocidal antimalarial activity and proteasome inhibition. This study describes a promising new class of antimalarial compound based on the carmaphycin B scaffold, as well as several chemical structural features that serve to enhance antimalarial specificity.

Chitosan-based nanocomposites for the repair of bone defects

Chitosan scaffolds of different deacetylation degrees, average molecular weights and concentrations reinforced with silica nanoparticles were prepared for bone tissue regeneration. The resulting nanocomposites showed similar pore sizes (<300 μm) regardless the deacetylation degree and concentration used in their formulation. Their mechanical compression resistance was increased by a 30% with the addition of silica nanoparticles as nanofillers. The biocompatibility of the three-dimensional chitosan scaffolds was confirmed by the Alamar Blue assay in human primary osteoblasts as well as the formation of cell spheroids indicative of their great potential for bone regeneration. In vivo implantation of the scaffolds in a mice calvaria defect model provided substantial evidences of the suitability of these nanocomposites for bone tissue engineering showing a mature and dense collagenous tissue with small foci of mineralization, vascularized areas and the infiltration of osteoblasts and osteoclasts. Nevertheless, mature bone tissue formation was not observed after eight weeks of implantation.

Profile formation of academic self-concept in elementary school students in grades 1 to 4

Academic self-concept (ASC) is comprised of individual perceptions of one’s own academic ability. In a cross-sectional quasi-representative sample of 3,779 German elementary school children in grades 1 to 4, we investigated (a) the structure of ASC, (b) ASC profile formation, an aspect of differentiation that is reflected in lower correlations between domain-specific ASCs with increasing grade level, (c) the impact of (internal) dimensional comparisons of one’s own ability in different school subjects for profile formation of ASC, and (d) the role played by differences in school grades between subjects for these dimensional comparisons. The nested Marsh/Shavelson model, with general ASC at the apex and math, writing, and reading ASC as specific factors nested under general ASC fitted the data at all grade levels. A first-order factor model with math, writing, reading, and general ASCs as correlated factors provided a good fit, too. ASC profile formation became apparent during the first two to three years of school. Dimensional comparisons across subjects contributed to ASC profile formation. School grades enhanced these comparisons, especially when achievement profiles were uneven. In part, findings depended on the assumed structural model of ASCs. Implications for further research are discussed with special regard to factors influencing and moderating dimensional comparisons.

Polydomy enhances foraging performance in ant colonies

Collective foraging confers benefits in terms of reduced predation risk and access to social information, but it heightens local competition when resources are limited. In social insects, resource limitation has been suggested as a possible cause for the typical decrease in per capita productivity observed with increasing colony size, a phenomenon known as Michener's paradox. Polydomy (distribution of a colony's brood and workers across multiple nests) is believed to help circumvent this paradox through its positive effect on foraging efficiency, but there is still little supporting evidence for this hypothesis. Here, we show experimentally that polydomy enhances the foraging performance of food-deprived Temnothorax nylanderi ant colonies via several mechanisms. First, polydomy influences task allocation within colonies, resulting in faster retrieval of protein resources. Second, communication between sister nests reduces search times for far away resources. Third, colonies move queens, brood and workers across available nest sites in response to spatial heterogeneities in protein and carbohydrate resources. This suggests that polydomy represents a flexible mechanism for space occupancy, helping ant colonies adjust to the environment.

Abstract P5-09-06: Ovarian reserve and response to controlled ovarian hyperstimulation (COH) in breast cancer women with and without BRCA mutation

Background: 6300 new cases of breast cancer arise in young women under 40 each year in France. Some of them are BRCA 1 or 2 mutation carriers. Most of them receive a potentially gonadotoxic chemotherapy while they have not yet completed their family. Since 2011, a systematic proposal of ovarian reserve follow-up and fertility preservation by oocyte freezing is provided to each young early breast cancer (BC) patients (pts) of our program (NCT 01614704). Preliminary results were presented at the SABCS in 2013. We now investigate the impact of BRCA mutation on the ovarian reserve and the ovarian response to simulation.

Methods: 115 young BC pts were systematically referred to a reproductive medicine centre before starting chemotherapy. Inclusion criteria were age 18 to 38, histologically confirmed invasive breast carcinoma, absence of metastases. According to their personal and familial history, genetic counselling was performed and if the patient met the criteria and agreed, BRCA genes were analysed. Pts in an adjuvant setting and who were asking for fertility preservation underwent COH during the interval between complete surgery and start of adjuvant chemotherapy. Ovarian stimulation protocol consisted in a conventional antagonist protocol with recombinant FSH starting on day 2 of the menstrual cycles. The GnRh antagonist was started on day of the COH and the final oocyte maturation was achieved by an injection of triptorelin 0.2 mg when at least 3 follicles reached 18 mm of diameter. All pts gave their informed consent for COH, egg/embryo freezing and follow-up.

Results: 115 pts achieved pre-treatment AMH and AFC assessment. 60 (52,1%) were eligible for COH in order to cryopreserve egg or embryos. BRCA analysis was performed in 83 pts. 23 did not meet the criteria or refused. 9 analyses are still in process. 17 (20.4%) pts were positive for BRCA mutation (BRCA1: 13; BRCA2: 4) and 66 were not. In the mutation carriers group (n=17), median age was 32 years (Range 25-37). Median initial AMH levels and AFC were 23 pmol/l (5.1–223) and 20 (6-100), respectively. Eight pts underwent COH. Median duration of stimulation was 9,5 days (8-13) with a median cumulative dose of gonadotropins of 2875 UI (1200-5450). The median number of vitrified oocytes was 5,5 (0-15). Two patients chose frozen embryo preservation (1 and 2 eggs respectively). In the non-carriers group (n=66), median age was 31 years (24-37). Median initial AMH levels and AFC were 23.4 pmol/l (0.8-136) and 24 (1-68). 27 pts underwent COH. Median duration of stimulation was 10 days (7-14). Dose of gonadotropins was 2700 UI (1365-5600). The median number of vitrified oocytes was 6 (0-18). The 3 patients chose eggs preservation (0.0 and 3 eggs respectively). There was no significant difference in the two groups.

Discussion/ Conclusion: Few studies stated that BRCA1 mutation may be associated with reduced ovarian reserve in healthy BRCA mutation carriers. Meirow and al concluded that both healthy and BC BRCA mutation carriers demonstrated normal ovarian response in vitro fertilization cycles. Our results show that ovarian reserve of BRCA 1/2 mutations BC carriers do not differ from that of non-carriers. Response to COH seems similar in both groups too.

Citation Format: Mailliez A, Keller L, Menu-Hespel S, Plouvier P, D'Orazio E, Basson L, Pigny P, Bonneterre J, Decanter C. Ovarian reserve and response to controlled ovarian hyperstimulation (COH) in breast cancer women with and without BRCA mutation [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-09-06.

The Genovese grading scale is not reliable for MR assessment of collagen meniscus implants

BACKGROUND

The purpose of the study was to evaluate the intra- and inter-observer reliabilities of the Genovese grading on MRI in patients after collagen meniscus substitution.

METHODS

84 MRI images of 74 consecutive patients who underwent partial meniscus substitution using collagen meniscus implant (CMI) were assessed. MRIs were evaluated using the Genovese grading system. Furthermore, meniscal extrusion was assessed. Two observers performed the grading twice, blinded to each other and to the previous results, with a six weeks interval. The inter- and intra-observer reliabilities were assessed using kappa and weighted kappa values.

RESULTS

The criterion "morphology/size" showed a weighted kappa value inter-observer reliability of 0.069 (rater 1)/0.352 (rater 2) and intra-observer reliability of 0.170 (1st rating)/0.582 (2nd rating). The criterion "signal intensity" showed a weighted kappa value inter-observer reliability of 0.175/0.284 and intra-observer reliability of 0.294/0.458. The criterion "cartilage lesions" showed a kappa value inter-observer reliability of 0.091/0.525 and intra-observer reliability of 0.409/0.413. The criterion "bone marrow edema" showed a kappa value inter-observer reliability of 0.667/0.808 and intra-observer reliability of 0.702/0.715. The criterion "cartilage lesions" showed a kappa value inter-observer reliability of 0.091/0.525 and intra-observer reliability of 0.409/0.413. Regarding meniscal extrusion kappa values for the inter-observer reliability were 0.625/0.940 and 0.625/0.889 for intra-observer reliability.

CONCLUSIONS

Three of the four Genovese grading items showed only slight to moderate inter- and intra-observer reliabilities in evaluating CMI on MRI. Hence, such grading results need to be considered with all due care. Only the criteria "bone marrow edema" and "meniscal extrusion" showed a good agreement for both inter- and intra-observer reliabilities.

A novel type of splayed ferromagnetic order observed in Yb2Ti2O7

The pyrochlore insulator Yb2Ti2O7 has attracted the attention of experimentalists and theoreticians alike for about 15 years. Conflicting neutron diffraction data on the possible existence of magnetic Bragg reflections at low temperature have been published. Here we report the observation of magnetic Bragg reflections by neutron powder diffraction at 60 mK. The magnetic diffraction pattern is analyzed using representation theory. We find Yb2Ti2O7 to be a splayed ferromagnet as reported for Yb2Sn2O7, a sibling compound with also dominating ferromagnetic interactions as inferred from the positive Curie-Weiss temperature. However, the configuration of the magnetic moment components perpendicular to the easy axis is of the all-in-all-out type in Yb2Ti2O7 while it is two-in-two-out in the Yb2Sn2O7. An overall experimental picture of the magnetic properties emerges.

Morphologic and Functional Heart Abnormalities Associated to High Modified Tei Index in Hypertensive Patients

INTRODUCTION

LV dysfunction develops early in hypertension, even previously to left ventricular remodeling.

AIMS

To determine the frequency of morphologic and functional heart abnormalities associated to abnormal modified Tei Index in untreated hypertensive (HBP) patients (p) with preserved ejection fraction (pEF).

METHODS

Case-control study. Three groups: (1) HBP without left ventricular hypertrophy (LVH); (2) HBP with LVH; (3) non-HBP controls. Ejection fraction >54 % identified pEF. LVH measured by Devereux method. Systolic and diastolic functions assessed by standard echocardiography and tissue Doppler. 2013 ESH/ESC Hypertension Guidelines normal values were considered. Tei index measured at the lateral and septal LV walls in apical 4-chamber view by tissue Doppler, value >0.40 considered abnormal.

STATISTICAL ANALYSIS

multifactorial ANOVA test adjusted by sex and age, p < 0.05 statistically significant.

RESULTS

The study included 14 controls, 88 HBP p without LVH, and 19 HBP p with LVH. The HBP p sample mean age was 58.7 ± 13.5 years and 52 (44.1 %) were males. Mean Tei Index was 0.35 ± 0.03 in controls; 0.42 ± 0.05 in HBP without LVH; and 0.42 ± 0.06 in HBP with LVH (p < 0.025). Abnormal Tei Index was present in 2p (14.3 %) controls; 64 p (72.7 %) HBP without LVH; and 15 p (78.9 %) HBP with LVH (p < 0.0009). Tissue Doppler's wave was 8.4 ± 0.9 cm/s in controls; 8 ± 1.6 cm/s in HBP without LVH and 7.8 ± 1.1 cm/s in HBP with LVH.

CONCLUSIONS

(1) Left ventricular dysfunction is frequent in HBP p, even without LVH; (2) modified tissue Doppler Tei index is a useful tool for the diagnosis of left ventricular dysfunction.

Three-dimensional Micro-culture System for Tooth Tissue Engineering

The arrangement of cells within a tissue plays an essential role in organogenesis, including tooth development. Progress is being made to regenerate teeth by reassociating dissociated embryonic dental cells and implanting them in vivo. In the present study, we tested the hanging drop method to study mixed epithelial-mesenchymal cell reorganization in a liquid instead of semisolid medium to see whether it could lead to tooth histogenesis and organogenesis. This method allowed the control of the proportion and number of cells to be used, and the forming microtissues showed homogeneous size. The liquid environment favored cell migrations as compared with collagen gels. Three protocols were compared. The one that sequentially combined the hanging drop and semisolid medium cultures prior to in vivo implantation gave the best results. Indeed, after implantation, teeth developed, showing a well-formed crown, mineralization of dentin and enamel, and the initiation of root formation. Vascularization and the cellular heterogeneity in the mesenchyme were similar to what was observed in developing molars. Finally, after coimplantation with a trigeminal ganglion, the dental mesenchyme, including the odontoblast layer, became innervated. The real advantage of this technique is the small number of cells required to make a tooth. This experimental model can be employed to study the development, physiology, metabolism, or toxicology in forming teeth and test other cell sources.